Richard Pajerski Software development and consulting

Entries tagged [java]

Three easy-to-use Java 17 features in Notes/Domino 14

by Richard Pajerski


Posted on Tuesday December 19, 2023 at 03:14PM in Technology


As I mentioned previously, having Java 17 available with the latest release of Notes/Domino has brought welcome changes for Java developers.  Just to scratch the surface a bit, here are three language-level niceties that we can immediately benefit from:


1.  Simplified access to file contents
2.  Local-variable type inference (var identifier)
3.  Text blocks


1.  Simplified access to file contents
Java has been (in)famous for offering a number of ways to open/read and write/close files.  As of Java 11, perhaps the simplest way to get text out of a file is:

Files.readString(Path p);



A two-liner in a local Java agent on a Windows 11 client:


import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

import lotus.domino.*;

public class JavaAgent extends AgentBase {

    public void NotesMain() {

      try {

          Path p = Paths.get("C:\\Windows\\System32\\drivers\\etc\\hosts");
          System.out.println(Files.readString(p)); 
      } catch(Exception e) {
          e.printStackTrace();
      }
   }
}

Javadoc:  https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/nio/file/Files.html#readString(java.nio.file.Path)


2.  Local-variable type inference (var identifier)

The var type identifier has been available since Java 10 and is intended to help reduce "boilerplate" code:

import lotus.domino.*;

public class JavaAgent extends AgentBase {

    public void NotesMain() {

      try {

         var s = getSession();
         var db = s.getCurrentDatabase();
         System.out.println("Db title: " + db.getTitle());

                /* Contrast:
                     Session s = getSession();
                     Database db = s.getCurrentDatabase();
                   */

      } catch(Exception e) {
          e.printStackTrace();
      }
   }
}

More: Using the Var Type Identifier


3.  Text blocks
In Java 15, Text Blocks were introduced.  In a more developed application, it's probably a better idea to store strings and text outside of source code, especially if they need to be regularly modified.  But using text blocks can be a time saver for quick testing, demos, etc. and provide improved source readability.

import lotus.domino.*;

public class JavaAgent extends AgentBase {

    public void NotesMain() {

      try {

         var textBlock = """

                Using text blocks in Java source

                code simplifies text formatting

                and improves readability!

                """;


         System.out.println(textBlock);


      } catch(Exception e) {
          e.printStackTrace();
      }
   }
}


Note: To use these features, remember to adjust your compiler levels appropriately:


Domino/Notes 14 and Java in the client

by Richard Pajerski


Posted on Wednesday July 26, 2023 at 01:25PM in Technology


Those who have been programming with Java in Notes/Domino over the years will be pleased to learn of the move from Java 8.x to Java 17 which is planned for the next release of ND 14 at the end of the year.  The version gap is rather stark and indeed a lot has changed.  One nice summary of the changes between the two version can be found at The Java Almanac here:  https://javaalmanac.io/jdk/17/apidiff/8/.

I've yet to explore the impact to the ND world in any detail but will try to cover that in some future posts.  A particular area of interest for me that's still "unresolved" is how HCL intends to treat Java applets.  Here I mean applets embedded in Notes client applications, not for use in web browsers.  Applets were deprecated for removal in Java 17 and of course have long been out of use in web browsers.  But will HCL continue to support their use in the Notes client and if so, for how long?


Possible bug with triggered NSFDBHOOK events in DOTS (on Windows 2019)

by Richard Pajerski


Posted on Friday December 23, 2022 at 01:13PM in Technology


[February 2023 update: DOTS follow-up, SPR for applet bug]

I recently took advantage of DOTS being back in the Domino 12 server, to replace a Java agent with a scheduled DOTS tasklet and have been pleased with the results.  Using tasklets is generally going to be far more efficient than using Java agents in Domino since a JVM is loaded once with the DOTS server task and remains resident in memory until the DOTS task is stopped whereas with each agent invocation a new instance of the JVM is started.  There are other benefits to using tasklets over Java agents which I may take up in a future post but for the moment, I've run across an issue on a Windows 2019 server installation.

Although the deployment above uses a scheduled tasklet, I was originally hoping to use the triggered NSFDBHOOK events in order to capture some document saves in (more/less) real time.  But while testing on Windows 2019, I noticed that the HOOK_EVENT_NOTE_UPDATE and HOOK_EVENT_NOTE_OPEN events were not being emitted at all or only very infrequently.  I had earlier tested the same tasklet on a Domino installation on a Windows 8.1 client and the events fired more/less as expected.  Aside from the OS difference, everything about the Domino installations was identical -- with one exception: the Domino program installation directory on the Windows client had no spaces but the Windows server was installed in the default C:\Program<space>Files\HCL directory.  Sure enough, after reinstalling Domino on the Windows 2019 server without the space (specifically in C:\Domino), events began firing again.  HCL has also reproduced this and may open an SPR.

In the meantime, after working a bit more with those NSF hook events, my impression is that they are not altogether reliable -- or at least, there doesn't appear to be a one-to-one correlation with each document save/open and a DOTS-generated event.  Some document saves/opens never fire an event.  The source code for the older versions of DOTS is on openntf.org here: https://stash.openntf.org/projects/DOTS/repos/dots/browse/sources but I'm not sure if this is the same code being shipped with the Domino 12 server (though I assume it's pretty close).

If I'm looking in the right place, lines 79 and 80 of the postMessage method (https://stash.openntf.org/projects/DOTS/repos/dots/browse/sources/dotsNSFHook.cpp), have:

STATUS error = MQOpen(queueName, 0, &dotsmq);
 if ( error == NOERROR ){

where DOTS presumably intercepts the necessary events from an internal Domino queue.  But what if there *are* errors here?  Will our DOTS tasklets ever know about them?  Maybe errors are unlikely here but perhaps this is the source of some missed events.


Java applets in Notes 64-bit client not loading

by Richard Pajerski


Posted on Wednesday December 21, 2022 at 07:17PM in Technology


[February 2023 update: DOTS follow-up, SPR for applet bug]

For the first time in the history of Notes, HCL last month released a fully supported 64-bit version of the Notes standard, Domino Designer and Domino Administrator clients with release 12.0.2.  Overall I've found it to be more stable and certainly faster than its 32-bit counterpart and so I now use it regularly.  However, it's not without its issues with reports popping up here and here.  And I have another to add: Java applets won't load in the 12.0.2 64-bit client.  I submitted a ticket to HCL and they could reproduce this so they're preparing an SPR.

A notable aspect of this bug is that there are no error logs (that I could find) to indicate something's wrong.  Nothing in the Java Debug console, the IBM_TECHNICAL_SUPPORT folder, log.nsf, etc.  You will see the Java coffee cup but I think most end users will not immediately interpret it as a problem:



This issue is probably not an inconvenience for most deployments since Java applets were never widely implemented in Notes (in my experience).  But where applets are used, they can bring quite a bit of power (e.g. custom interfaces for any third-party system with a Java API -- databases, message queues and so on).  The good news is that applets do still work in 32-bit Notes 12.0.2 and will likely be supported in Notes as long as Java 8 remains the default runtime.



Brief overview of modern (2021) server-side development landscape in Domino

by Richard Pajerski


Posted on Thursday October 07, 2021 at 08:21PM in Technology


Among the technical reasons Domino has enjoyed longevity in the application server market are its stability and reliability.  But of course technology changes rapidly and being able to successfully adapt to new trends has also kept Domino relevant over the years.  Striking a balance between trendy and relevant is not always obvious but the stewards of Domino have generally taken a conservative approach to introducing and supporting new technology which continues to benefit the product in the immediate and long term.

Very briefly then, beyond the tried-and-true world of Notes client server application development, let's look at three modern technology options developers can choose from in 2021:

1.  Domino AppDev Pack (https://doc.cwpcollaboration.com/appdevpack/docs/en/homepage.html)

From the site:  "The AppDev Pack primarily adds Node.js support to HCL Domino Server."

So developers already familiar with or wanting to explore the JavaScript-centric Node.js have a custom-designed set of tools for programmatically and securely accessing Domino applications and data.


2.  Domino REST API (Project Keep) (https://opensource.hcltechsw.com/domino-keep-docs/)

From the site: "Domino REST API is designed to re-establish Domino as a world class, modern, standards-compliant, cloud native and enterprise-level collaboration platform. It adds contemporary REST APIs to Notes and Domino, enabling a modern programming experience with the tools of your choice."

This is still in beta but will hopefully be out in Domino 12.0.1 later this fall.  Domino has for many years had the ability to offer data via a REST API (Domino Access Services) but Keep modernizes that effort by implementing (among other things) OpenAPI and JWT Authorization.  In addition, developers will be able to introduce their own server-side modules called "verticles" as Keep runs on top of Vert.x.


3.  Tasklets with DOTS - Domino OSGi Tasklet Service (https://help.hcltechsw.com/domino/12.0.0/admin/wn_dotsredux.html)

From the documentation: "DOTS is a generic Domino add-in task that lets users create Domino server tasks by creating a tasklet container using Java OSGi plugins."

Ok, this is not exactly modern -- DOTS was an OpenNTF project that's been available since Domino 8.5.3.  Although officially dropped in the Domino 10/11 era it was recently updated and re-introduced in Domino 12.

Strictly-speaking, DOTS is the Domino server task that manages the tasklets which are Java server-side plugins.  Tasklets use a standard mechanism for starting/stopping (OSGi-defined) which makes them similar to Java agents but have the additional benefits of (a) not being tied to a specific .nsf file, (b) not requiring a full JVM reload on every execution and (c) better access to the Domino C API.


How are you developing Domino server-side code these days?


Eclipse J9 is a big deal

by Richard Pajerski


Posted on Friday March 15, 2019 at 11:59PM in Technology


Having developed with Java for a number of years in various environments (Notes/Domino, Tomcat, ActiveMQ,  Android, desktop, etc.), I was initially skeptical when I read this article and watched the video about the recently-improved Eclipse OpenJ9: https://developer.ibm.com/videos/introduction-to-eclipse-openj9-and-adoptopenjdknet/

Yes, Java has incrementally improved over time but the claims here seemed a bit over the top.  To think I might get both noticeably faster startup *and* up to 50% memory reduction just by switching to J9 seemed to be a bit too optimistic.  But after downloading (adoptopenjdk.net) and giving it a spin, I was not disappointed.

Sure enough, out-of-the-box startup time for Netbeans 8.2 on Windows 8.1 increased dramatically against Oracle Java 1.8.0_191 (running quad-core I7 on SSD).  There was no point in taking measurements -- it was up and ready in three seconds!  This didn't seem possible with Netbeans but there it was.  Everything worked the same as before ... only faster.  Then the real shocker: RAM usage went from roughly 650M down to 268!  Huh?  If I can eliminate that much RAM usage for hosted server side deployments, it's going to translate into real cash savings.

On top of the performance upgrade and memory savings, I immediately noticed that Swing is visually better in J9 than OpenJDK [edit: with the HotSpot VM].  In particular, the default font rendering is really nice!  In the past, OpenJDK has generally lagged behind Oracle Java for desktop applications and still does; but to my eyes, J9 is now at visual parity with Oracle (or perhaps better).

I realize that the J9 has been the JVM in Notes/Domino all these years but I've never attempted to benchmark it against other JVMs since IBM never really promoted it as a JDK for Windows.  I'm currently using 9.0.1 FP10 which uses build 8.0.5.21 of J9:


notesjvm.png

Hopefully, IBM can manage to get the latest J9 into an upcoming fixpack.  I sure have lots of Notes and Domino Java code that could benefit from it.

A big congratulations and thank you to Mark Stoodley and all the other engineers and players behind this release!


Part 3. Extending the GUI of native Notes apps with Java applets

by Richard Pajerski


Posted on Wednesday April 01, 2015 at 11:12AM in Tutorials


*** July 2018 UPDATE ***
Links to the final database and Java source are included at the bottom of this blog entry.

In Parts 1 and 2, we created a Java applet and incorporated it into a Notes database. In this last part, we're going to code the export functionality in our applet and refresh the applet in Notes.

===================================
Part 3 -- Export Notes data using the applet
===================================

Step 1. Program the Start button. Open the ContactExport class in NetBeans and at the top of the code editor, click the Design button for the visual representation of the applet. Then right-click on the Start button and then Events > Action > actionPerformed. NetBeans will create a method called jButton1ActionPerformed and place our cursor at the appropriate spot in the source where we can add code that executes when the button's clicked. So we start with:


private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}

When we click the Start button, we want to immediately disable it so only one export operation runs at a time. This would normally just be the following one line of code:


jButton1.setEnabled(false);

However, in Swing, we need to make sure to put any code that updates the UI on the event dispatch thread. So we're going to disable the button in a new thread:


private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try {
java.awt.EventQueue.invokeAndWait(new Runnable() {
public void run() {
jButton1.setEnabled(false);
}
});
} catch (Exception ex) {
ex.printStackTrace();
}
}


Step 2. Create a separate thread to access our Notes database. Next, we're going to create a separate thread that will connect to Notes. For now, we're going to implement this as a private inner class inside our applet. Toward the bottom of our ContactExample class, add:


private class ExportRunner implements Runnable {

private Thread t;

@Override
public void run() {

}

public void start() {
t = new Thread(this);
t.start();
}
}



We're going to place most of our functional export code in the ExportRunner's run() method which is the method that gets called when we start a Java thread. Add the following block to the ExportRunner's run() method to access the "All Contacts" view and its documents:


@Override
public void run() {
try {
Session s = ContactExport.this.openSession();
Database db = s.getDatabase("", "Contacts.nsf");
View allContactsView = db.getView("AllContacts");
Document d = allContactsView.getFirstDocument();
while (d != null) {
// We access the data here...
Document tmpDoc = allContactsView.getNextDocument(d);
d.recycle();
d = tmpDoc;
}
allContactsView.recycle();
db.recycle();
} catch (NotesException nex) {
nex.printStackTrace();
}
}


Step 3. Cycle through the contact documents and save the contents to internal buffer. First, add a StringBuilder in the ExportRunner class which will serve as the internal buffer to store the comma-delimited data. Also declare a platform-independent line separator.


private class ExportRunner implements Runnable {
private Thread t;
private StringBuilder sb = new StringBuilder();
private String newline = System.getProperty("line.separator");



Back in ExportRunner's run() method, we next want to update the while loop to extract the contact field data and separate the fields with commas and a final carriage return at the end of each line:


while (d != null) {
String firstName = d.getItemValueString("FirstName");
String lastName = d.getItemValueString("LastName");
String phone = d.getItemValueString("Phone");
String city = d.getItemValueString("City");
sb.append(firstName);
sb.append(",");
sb.append(lastName);
sb.append(",");
sb.append(phone);
sb.append(",");
sb.append(city);
sb.append(newline);
Document tmpDoc = allContactsView.getNextDocument(d);
d.recycle();
d = tmpDoc;
}


Step 4. Update the progress bar as we go through the contacts. This may sound straightforward but it takes some setup. Let's start by adding these variables to the ExportRunner class, just below the StringBuilder declaration:


private class ExportRunner implements Runnable {
private Thread t;
private StringBuilder sb = new StringBuilder();
private String newline = System.getProperty("line.separator");
private int contactCount;
private javax.swing.Timer progBarTimer;



NetBeans' GUI builder will have already declared a JProgressBar for us using the variable name jProgressBar1 when we added the progress bar component to our JPanel back in Part 1. But to animate the JProgressBar, we need to create two additional items: a handler class and timer class. We're going to create the handler class as a new private inner class in the ExportRunner class. We'll call it ProgressBarHandler:


private class ProgressBarHandler implements ActionListener {
@Override
public void actionPerformed(ActionEvent event) {
int v = contactCount;
if (v != 0) {
jProgressBar1.setValue(v);
}
}
}


And we'll instantiate the Timer class by inserting this as our first line in the run() method of our ExportRunner class:


progressBarTimer = new javax.swing.Timer(2, new ProgressBarHandler());

The Timer takes our handler class as a parameter and, once started, will call its actionPerformed method every two milliseconds. In actionPerformed, we explicitly set the progress bar's value. When the thread starts, we start the Timer, prime the progress bar with starting and ending values and then update those values as we loop through the documents.

We're also going to add a new method to ExportRunner called isDone() that holds a boolean variable indicating when the export is complete. We set the boolean variable to true when we're done processing the documents and when the handler sees that, it sets the progress bar back to zero and stops the Timer. It also takes care of re-enabling our Start button.

Beyond the progress bar animation, a good GUI practice is to let the user know when the system is busy. We're going to do that with the following commands:


setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));

Place the WAIT_CURSOR command outside the ExportRunner class – at the beginning of the jButton1ActionPerformed method and put the DEFAULT_CURSOR command as the last line in the handler class.

Here's the latest version of ExportRunner:


private class ExportRunner implements Runnable {

private Thread t;
private StringBuilder sb = new StringBuilder();
private String newline = System.getProperty("line.separator");
private int contactCount;
private javax.swing.Timer progressBarTimer;
private boolean done = false;

@Override
public void run() {

try {
progressBarTimer = new javax.swing.Timer(2, new ProgressBarHandler());

Session s = ContactExport.this.openSession();
Database db = s.getDatabase("", "Contacts.nsf");
View allContactsView = db.getView("AllContacts");

// Set the progress bar's minimum and maximum values.
jProgressBar1.setMinimum(0);
// Total contact documents in our view.
jProgressBar1.setMaximum(allContactsView.getEntryCount());

// Start the timer.
progressBarTimer.start();

Document d = allContactsView.getFirstDocument();

while (d != null) {
Thread.sleep(1); // Pause this loop to give other threads a chance to run.
contactCount++; // Increment the number of contacts processed.

String firstName = d.getItemValueString("FirstName");
String lastName = d.getItemValueString("LastName");
String phone = d.getItemValueString("Phone");
String city = d.getItemValueString("City");
sb.append(firstName);
sb.append(",");
sb.append(lastName);
sb.append(",");
sb.append(phone);
sb.append(",");
sb.append(city);
sb.append(newline);
Document tmpDoc = allContactsView.getNextDocument(d);
d.recycle();
d = tmpDoc;
}
allContactsView.recycle();
db.recycle();

} catch (NotesException nex) {
nex.printStackTrace();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
done = true;
}
}

public void start() {
t = new Thread(this);
t.start();
}

private boolean isDone() {
return done;
}

private class ProgressBarHandler implements ActionListener {

@Override
public void actionPerformed(ActionEvent event) {
int v = contactCount;
if (v != 0) {
jProgressBar1.setValue(v);
}
if (ExportRunner.this.isDone()) {
progressBarTimer.stop();
jProgressBar1.setValue(0);
jButton1.setEnabled(true);
setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
}
}



Finally, to instantiate and run this new class when the Start button is clicked, go back to jButton1ActionPerformed and add these two lines to the run() method:

ExportRunner exportRunner = new ExportRunner();
exportRunner.start();

The actionPerformed method should now look like:


private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
jButton1.setEnabled(false);
ExportRunner exportRunner = new ExportRunner();
exportRunner.start();
}


Step 6. Store the output after prompting the user for a location. Our data is now in our StringBuilder object but in Java, it takes a few steps to get that data into a file. For additional flexibility, we're also going to prompt the user for a file name and location using a JFileChooser. Put this block just after the db.recycle() command in ExportRunner's run() method:


JFileChooser jFileChooser = new JFileChooser();
jFileChooser.setSelectedFile(new File("ExportedContacts.txt"));
int save = jFileChooser.showSaveDialog(ContactExport.this);

if (save == JFileChooser.APPROVE_OPTION) {
FileOutputStream stream = null;
PrintStream out = null;
try {
File file = jFileChooser.getSelectedFile();
stream = new FileOutputStream(file);
out = new PrintStream(stream);
out.print(sb.toString());
} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
if (stream != null) {
stream.close();
}
if (out != null) {
out.close();
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}



That's it for the code. Now recompile the applet and refresh it in Notes (see Step 5 of Part 2). Populate the Notes database with some sample contact data and try it out.

Conclusion
Embedding custom Java applets in the Notes client is a powerful way of extending the value of Notes client applications. It's a little more involved than building out similar functionality with traditional Notes design elements but it offers benefits that just aren't available in Notes. Considering the size of the Java API and availability of third party Java-based tools, this example only scratches the surface of the possibilities.

Files and source code
Contacts.nsf.zip
ContactExport-src.zip


Part 2. Extending the GUI of native Notes apps with Java applets

by Richard Pajerski


Posted on Thursday March 26, 2015 at 11:27PM in Tutorials


In Part 1, we created a Java applet using NetBeans that will allow us to export Notes contact data. In this second part, we're going to walk through getting that applet set up properly in a Notes database. I've created a small database called Contacts and populated it with several contact documents, each with only four fields: First Name, Last Name, Phone and City. In order to highlight the basic goal of applet integration, I'm only going to discuss the database design aspects directly related to the applet.

========================================
Part 2 -- Integrating the applet in the Notes Client
========================================

Step 1. Compile the project in NetBeans. First compile the applet (right-click on the project then Clean and Build). This step will produce a file called ContactExport.jar, which will be created in the project's dist folder.

Step 2. Create a Page element and embed the applet in it. In Domino Designer, create a new Page design element called ContactApplet. Open the page, hit Enter at least once to produce a small page header and then type Export Contact List. Hit Enter again and from the menu, Create > Java Applet. You'll first be presented with a Create Java Applet dialog; click the Locate button in the lower right to get the Locate Java Applet Files dialog. Now click the folder icon beside the Base Directory field to navigate to our project's dist folder (in my case, D<colon><backslash>temp<backslash>ContactExport<backslash>dist). Click Ok and you should now see the ContactExport.jar file. Click Add/Replace File(s) and in the Base class field at the top right, enter com.example.ContactExport.class (which is our applet's main class file). Click Ok twice and save the Page.

CreateJavaApplet.png LocateJavaApplet.png ContactPage.png

Step 3. Link the ContactExport Page element to the default Outline. The Contacts database uses a Frameset and Outline for the main navigation where clicking on the left-hand navigation places the view or page on the right frame. I've already created a default Outline called Main that displays the database's views and now we're going to add an entry to the Outline. The entry will be the ContactExport Page element from Step 2.

ContactOutline.png

At this point, the applet is ready to work in the Notes client. However, we'll need to make some minor adjustments to both the applet and page to improve the presentation.

Step 4. Change applet look and feel and adjust border. For better visual integration, we're going to tell the applet to use the "system" look and feel so that it fits in better with the underlying platform (in this example, Windows 8). In the notesAppletInit method, expand the section labelled "Look and feel setting code". Remove the for{} block and replace it with:

javax.swing.UIManager.setLookAndFeel(javax.swing.UIManager.getSystemLookAndFeelClassName());

This tells Java to pick up the native look and feel for the underlying platform. In addition, since we're only going to be displaying a button and progress bar, we're also going to shrink the applet window size. Simply grab the frame of the applet in the GUI builder and drag to resize. Once you have an appropriate size, double-click the border and record the applet's width and height -- we'll need to use these dimensions for the embedded applet in the page design element.

NotesAppletInit.png RemoveNimbus.png SetLookAndFeel.png ChangeBorder.png



Step 5. Update the page and resize the applet. Be sure to Clean and Build the project again in NetBeans so that a new applet jar file is created in the project's dist directory. Now go back to the ContactApplet page in Domino Designer, right-click on the embedded applet, click Refresh from the menu then Refresh All; click Ok and save the page.

Next, resize the applet in the page to match the dimensions from the applet's window size from NetBeans (Step 4 above). Unfortunately, this must be done with the mouse -- the size properties on the Java Applet properties box is read only.

ResizeNotesApplet.png

Finally, I'm going to change the background color of the page to light gray to better blend with the applet and move applet slightly towards the left margin (Text Properties box).

PageColor.png

And here's what we have so far:

NotesApp1.png



In Part 3, we'll code the applet to select documents from the Notes view and export them to a comma-delimited file.


Part 1. Extending the GUI of native Notes apps with Java applets

by Richard Pajerski


Posted on Tuesday March 24, 2015 at 12:28PM in Tutorials


Notes/Domino application development has for years targeted the web browser for the GUI but for many organizations, a large portion of apps are written for the native Notes client. While a common path for extending these native apps is to develop a portion of them as web apps, another powerful way is to implement Java applets in forms and pages. Even though Java applets were initially intended for web browsers, we can use use them as though they were native Notes widgets right in the Notes client.

The ability to embed Java applets in the Notes client has been available since Java itself was introduced into the environment way back in the 4.x days. However, applets were a tough sell then for a number of reasons, among them slow load times and sub-par look and feel. It wasn't until Java 6 was available in the 8.x client – a dozen years later – that custom applets became a realistic option for production Notes apps.

Let's look at a custom applet that can retrieve a contact list from a Notes 9 database and let the user export that data to a comma-delimited file. For this example, I'm using the NetBeans IDE (version 8.02) to develop the applet. The applet will compile to a jar archive which we'll import into the Designer client. Familiarity with Java and using Domino Designer will be assumed but since NetBeans and Java Applets in particular are not commonly used in Notes development, I'll try to be a bit more detailed when referring to them.

In Part 1, we'll set up the applet project in NetBeans. In Part 2, we'll walk through getting the applet integrated in Notes. Finally, in Part 3, we'll code the applet source with the main functionality and then refresh the Notes database with the updates.


=================================
Part 1 -- Setting up the NetBeans project.
=================================

Step 1. Create a new Java Project. From the menu, Start > New Project and choose new Java Application. I'm calling the new project ContactExport and using com.example as the default package.

NewJavaProject.png NewJavaFolder.png

By default, this creates a class file called ContactApplet but we're not going to use it. We're going to create a JApplet Form (Step 2) file and use that instead so the ContactApplet file can safely be deleted.

Step 2. Create a JApplet. Create a new JApplet form in the com.example package called ContactExport. This allows us to use the GUI builder in NetBeans which can greatly simplify designing a Swing-based user interface.

CreateJApplet.png NewJAppletForm.png

Step 3. Set Source/Binary Format to JDK 6 and add NCSO.jar as a library. Right-click on the project, then Properties, Source and make sure that the Source/Binary Format (at the bottom of the dialog) is set to JDK 6 which matches the JRE version on Notes 9. Next, in the same dialog, click Librairies on the left-hand navigation and then on the right, Add JAR/Folder. Here we add the NCSO.jar (found in the Notes\Data\domino\java directory) as a library for this project to expose the Notes Java API.

SourceFormat.png NCSO.png

Step 4. Extend JAppletBase. By default, the applet extends javax.swing.JApplet but let's change that to extend lotus.domino.JAppletBase. Next, click the light bulb in the left margin to import the lotus.Domino.JAppletBase package.

ExtendJAppletBase.png

Step 5. Update init() method. Change the applet's init() method to notesAppletInit(). Since we've changed our default class from javax.swing.JApplet to lotus.domino.JAppletBase, we need to use this new method to initialize the applet.

NotesAppletInit.png

Step 6. Add components to the applet. Switch to Design mode (click 'Design' at the top of the source Editor) and drag and drop a JPanel to the applet background; then size it till it covers the entire visual space of applet. Next, add a Start button (JButton) and a progress bar (JProgressBar) to the JPanel. Right-click on the button, click Edit Text and change to name to Start.

JPanel.png JButton.png JProgressBar.png



That completes getting the basics of the applet itself set up. We'll cover making it functional in Part 3. But next, in Part 2, we're going to import the applet into Notes using Domino Designer and show how to embed it in a Notes Page design item.